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(No Model.)

- R. LE LAS & A. ROBIN.

PURNAGE.

No. 411,865. Patented Oct. 1, 1889.

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UNITED STATES PATENT @rrrcn.

ROBERT LE LAS, OF ALHUT TREE, NEAR CARDIFF, ENGLAND, AND ALBERT ROBIN,OF PARIS, FRANCE.

FURNACE.

SPECIFICATION forming part of Letters Patent No. 411,865, dated October1, 1889.

Application filed July 12, 1888. Serial No. 280,140. (No model.)Patented in England A ril13, 1888, No. 5,527.

To aZZ whom it may concern:

Be it known that we, ROBERT LE LAS, a citizen of the Republic of France,residing at lValnut Tree, near Cardiff, England and AL- BERT ROBIN, acitizen of the Republic of France, residing at Paris, France, haveinvented certain new and useful Improvements in Furnaces for BurningSmall Fuel, of which the following is a specification.

This invention has been patented in Great Britain by Letters Patentdated April 13, 1888, No. 5,527.

The combustion of small fuel upon a furnace-grate involves two essentialconditions.

viz., first, reducing to the minimum the spaces between the gratebars,while still furnishing space amply suflicient for the passage of the airnecessary for the combustion; second, by reason of the nature of thecoal, which necessitates contracted spaces between the gratebars, it isnecessary to convey the air under the grate by force in order to pass itthrough the bed of fuel; but under the influence of a forced blast thecombustion is carried on at a high temperature, and hence the grate-barsbecome clogged by the clinkers, which an here thereto and obstruct thepassage of the air.

It has hitherto been proposed to cool the grate-bars by the circulationof water; but the means heretofore employed have necessitated verycomplicated arrangements and constructions of the grate-bars,supply-ducts, &c. o, however, here propose to present a system forgrates which permits the effecting of the combustion by a forcedair-blast, and which at the same time insures the cooling of thegrate-bars. This last result is obtained by previously rendering the airmoist before it is brought beneath the grate. This moist air arrivingunder the grate, the water with which it. is charged is vaporized oncontact with the grate-bars, and in consequence it lowers thetemperature. The clinkcrs hence do not adhere to the grate-bars and thegrate is maintained in proper condition. In order to effect thisintroduction of moist air, we cause the air furnished by a blower, fan,bellows, or other convenient ainpump to pass through a current or sprayof water, which saturates the air with a sufficient moisture before itarrives beneath the grate.

As an example, and in order to make our invention clearly understood, wehave illustrated in the accompanying drawings our systom applied to afurnace for generating steam.

Figure l is a longitudinal section of the grate. Fig. 2 is a face viewof the front of the furnace and a section of the apparatus whichmoistens the air to be supplied to the furnace. Fig. 3 is a sectionalview of amodified air-moistening apparatus. Figs. 4 and 5 are end andside views, respectively, of the sections composing the grate-bars.

The air necessary for the combustion furnished by a fan V is introducedunder the grate G by an air-inlet channel B, which is affixed to thefront of the ash-box A or at any other convenient location. Thisair-channel may be removed for the withdrawal of the ashes and theclearing of the ash-box. Between the fan and the fixed air-inlet channelis located the apparatus for moistening the air, Which is susceptible ofa variety of constructions. When the system is to be applied to a marineboiler, we prefer to adopt the arrangement shown in Fig. 2 of thedrawings, because it is not affected by the variations in theinclination of the surface of the water in the apparatus, and it insuresa uniform and constant moistening action. The air arrives from the fan Vthrough a pipe T,bent around into a metal casing 0, from the upper partof which a discharge-pipe D for the air leads to the air-inlet channelB. The open end of the pipe T within the casing C is surrounded by afunnel-shaped box or frame E, into which is introduced water by a pipe25, andinto which the waterfalls in a showeror spray all around the openend of the air-inlet pipe T. The air forced out of the pipe T in orderto pass out through the discharge-pipe D is obliged to pass through theliquid sheet, and is thus charged with water. The water which falls tothe bottom of the casing Uis carried off by a pipe 00.

In order to diminish as far as possible the amount of water to besupplied, it is useful to place upon the funnelsl1aped box or frame E,reaching down to the bottom of the casing C,

coarsely -woven cloths or fabrics, which by capillary attraction willretain water in their meshes, whereby the air will be obliged, in

passing through the cloths, to become satu-.

rated with moisture.

In case the apparatus is to be adapted to stationary boilers, the casingcan be arranged for moistening the air as shown in Fig. 3. The airenters into the casing by a pipe F at the bottom and passes out throughthe pipe D at the top, as in Fig. 2. In the interior of this casing,near the top, is arranged a perforated sheet-metal plate G, whichreceives Water from the pipe t. The water fallsin aspray through theperforations in the plate G in a direction opposite to the movement ofthe air throughout the height of the casing. By suitably regulating thevelocity of the incoming air there can be given to the air the desireddegree of moistness.

The grate is formed of bars constructed as is shown on a larger scale inFigs. 4 and 5. The bars X are made of thin sheet metal, of great heightas compared with their thickness, and they are maintained at the desireddistance apart by means of sheet-metal washers r interposed betweenthem. The bars X are bound together in groups of any desired number(five, the number shown, being a suitable number) by means of tie-bars eriveted thereto. These groups of bars are arranged in the fire-box inthe usual manner, and rest upon transverse beams s. The bars may,however, be arranged transversely and the beams longitudinally equallyWell. The grate-bars of this described construction are especiallysuitable for marine boilers, where itis necessary to attain a maximumpower in a confined space, the great height given to the bars resultingin presenting the greatest possible surface for the contact of the moistair.

With furnaces supplied with a forced airblast, in which the combustionis very active, it often happens that the furnace-doors become highlyheated. This causes a rapid deterioration of the doors and muchsuffering for the fireman. \Ve avoid this inconvenience and annoyance byforming in the crossplate 19 in front of the grate a vent-passage f,through which can pass a small quantity of the moist,air introducedunder the grate.

The furnace-door has double walls, and the vent f communicates with thespace between the Walls. The air thus enters this space and cools thedoor, and, being itself there heated, passes out into the combustion-chamber above the burning fuel, assisting in consuming the smoke wheneversoft coal is employed. The

vent f is controlled by a door or valve which may be adjusted by thefireman at will to reg-- ulate the passage of moist air into theinterior of the door. I

A portion of the air passing through the fan can be carried into theboiler and engine rooms, thereby ventilating the same and lowering thetemperature, which ordinarily is so trying and fatiguing to the,engineers and firemen.

For large plants comprising a number of steam-generators there may beemployed, instead of a fan, an air-pump for forcing the air into areservoir having anumber of branch pipes leading to the severalfire-boxes of the different generators.

WVe claim as our invention- 1. The grate of a furnace and an air-pumpfor supplying air under pressure beneath said grate, in combination withan intervening air-moistening device consisting of a casing, anair-inlet leading from the pump and conducting air to the lower part ofthe casing, an air-outlet to the furnace, leading from the upper part ofthe casing, whereby the air under pressure is forced upwardly throughthe casing, a water-inlet pipe entering the upper part of the casing,and a water-distributer adapted to subdivide the water and cause it todescend through the casing in such manner as to intercept and minglewith the ascending air, whereby the latter is caused to pass through thedescending water and become thoroughly moistened thereby.

2. The grate of a furnace and an air-pump for supplying air beneath thesame, in combination with a casing, an air-inlet pipe leadin g from thepump to the casing, an air-outlet pipe leading from the casing to thefurnace, a cloth or fabric arranged within the casing to be traversed bythe air in passing from the inlet to the outlet pipes, and a water-inletconducting water to said fabric to keep it saturated, substantially asset forth.

3. The grate of a furnace and an air-pump for supplying air beneath thesame, in combination with a casing, an air-inlet pipe leading from thepump to the casing, an air-outlet pipe leading from the casing to thefurnace, a frame or box within the casing inclosing the mouth of theair-inlet pipe, a cloth or fabric covering said frame or box, and awater-inlet pipe conduct-ing water to said casing for keeping said clothsaturated, substantially as set forth;

In witness whereof we have hereunto signed our names in the presence oftwo subscribing witnesses.

ROBERT LE LAS. ALBERT ROBIN.

\Vitnesses for Le Las:

O. J. HUXTABLE,

28 Lowdown Square, Cardif JOHN WILLIAM BRADLEY,

.No. 1 Topaz St, Cardifi Vitnesses for Robin:

RoBT. M. HooPER, AMAND BITTER.

